Nickshu

Just did the recalibration using Forscan in my 2020 F-150 for the larger 275/60/20 tires I installed (K02s). No issues with any CEL or Airbag lights after the recalibration. Speedometer is now accurate again against a GPS app.

jblr83

Same for me, just did the recalibration 2 days ago with Forscan, with bfg ko2’s 315/70/17.
Before speedo showed 100km/h as I was at 107 with 2 different gps apps.
Only took a few minutes to do this, and now it’s perfect !

user 872308923

SIAP, for those of us who are FORscan deficient, wouldn’t even an average Ford dealership have something like this in their service Dept to recalibrate speedometers?
I’m in central Florida and would pay someone to do it when that time comes, but since I don’t know anyone that can, I’m at the mercy of my dealership. ( just got the truck Saturday so that mod is a few months away.)

SWO

The Ford dealerships can apparently only reprogram to tire sizes which were actually available from Ford.

OCLandspeeder

I did the speedo re-calibration using Forscan. Probably one of the easiest things to do.

You have to follow the instructions. Watch Youtube video. The Forscan software isn't perfectly clear as it uses Icons and if you're not familiar with those icons and which to click on then it won't be intuitive. That's why watching the Youtube video helps a lot. Read how it's done, know the exact code for the right size tire, then plug that in. But it took me 10 minutes, $50 for the OBD reader that Forscan recommends.

Dealership will charge you a ridiculous amount and newer F150's (maybe from 2015 & newer, not 100% sure) cannot be re-calibrated by dealer.

Summit151

Hello everyone. I used the calculator in google docs to find my value to enter. I did that but it made my Speedo out further now? I am about 4-5% out now. What other options do I have to fix this?

tland4

Use one of the pre-registered (for lack of better term) tire sizes for a tire that's the same size as yours.

For example, I have Mickey Thompsons that are 35x12.5x20, which weren't listed. The Toyo Open Country's which were the same size were already pre-registered in FORScan, so I selected those to calibrate my speedometer with. My MPH is dead on against GPS and those radar speed limit signs.

52merc

What tires do you have and what change did you make?

agtex42

I ran into the same problem with the “canned” solutions in the Forscan sticky thread. Ended up using the spreadsheet in the below link and it worked like a champ, it took two fine tune adjustments after verifying against a GPS but was able to get my speedometer within a tenth of the gps.

https://forscan.org/forum/viewtopic.php?t=2650